Effect of Low-dose and Standard-dose Aspirin on PGE2 Biosynthesis Among Individuals with Colorectal Adenomas: A Randomized Clinical Trial

Low-dose aspirin is recommended by the U.S. Preventive Services Task Force for primary prevention of colorectal cancer in certain individuals. However, broader implementation will require improved precision prevention approaches to identify those most likely to benefit. The major urinary metabolite of PGE2, 11α-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (PGE-M), is a biomarker for colorectal cancer risk, but it is unknown whether PGE-M is modifiable by aspirin in individuals at risk for colorectal cancer. Adults (N = 180) who recently underwent adenoma resection and did not regularly use aspirin or NSAIDs were recruited to a double-blind, placebo-controlled, randomized trial of aspirin at 81 or 325 mg/day for 8-12 weeks. The primary outcome was postintervention change in urinary PGE-M as measured by LC/MS. A total of 169 participants provided paired urine samples for analysis. Baseline PGE-M excretion was 15.9 ± 14.6 (mean ± S.D, ng/mg creatinine). Aspirin significantly reduced PGE-M excretion (-4.7 ± 14.8) compared with no decrease (0.8 ± 11.8) in the placebo group (P = 0.015; mean duration of treatment = 68.9 days). Aspirin significantly reduced PGE-M levels in participants receiving either 81 (-15%; P = 0.018) or 325 mg/day (-28%; P < 0.0001) compared with placebo. In 40% and 50% of the individuals randomized to 81 or 325 mg/day aspirin, respectively, PGE-M reduction reached a threshold expected to prevent recurrence in 10% of individuals. These results support that aspirin significantly reduces elevated levels of PGE-M in those at increased colorectal cancer risk to levels consistent with lower risk for recurrent neoplasia and underscore the potential utility of PGE-M as a precision chemoprevention biomarker. The ASPIRED trial is registered as NCT02394769.

Balloon catheter-based radiofrequency ablation monitoring in porcine esophagus using optical coherence tomography

We present a microscopic image guidance platform for radiofrequency ablation (RFA) using a clinical balloon-catheter-based optical coherence tomography (OCT) system, currently used in the surveillance of Barrett's esophagus patients. Our integrated thermal therapy delivery and monitoring platform consists of a flexible, customized bipolar RFA electrode array designed for use with a clinical balloon OCT catheter and a processing algorithm to accurately map the thermal coagulation process. Non-uniform rotation distortion was corrected using a feature tracking-based technique, which enables robust, frame-to-frame analysis of the temporal fluctuation of the complex OCT signal. With proper noise calibration, precise delineation of the thermal therapy zone was demonstrated using cumulative complex differential variance in porcine esophagus ex vivo with the integrated OCT-RFA system, as validated by nitroblue tetrazolium chloride (NBTC) histology. The ability to directly and accurately visualize the thermal coagulation process at high resolution is critical to the precise delivery of thermal energy to a wide range of epithelial lesions.

Tethered capsule endomicroscopy for microscopic imaging of the esophagus, stomach, and duodenum without sedation in humans (with video)

BACKGROUND AND AIMS

Patients with many different digestive diseases undergo repeated EGDs throughout their lives. Tethered capsule endomicroscopy (TCE) is a less-invasive method for obtaining high-resolution images of the GI mucosa for diagnosis and treatment planning of GI tract diseases. In this article, we present our results from a single-center study aimed at testing the safety and feasibility of TCE for imaging the esophagus, stomach, and duodenum.

METHODS

After being swallowed by a participant without sedation, the tethered capsule obtains cross-sectional, 10 μm-resolution, optical coherence tomography images as the device traverses the alimentary tract. After imaging, the device is withdrawn through the mouth, disinfected, and reused. Safety and feasibility of TCE were tested, focusing on imaging the esophagus of healthy volunteers and patients with Barrett's esophagus (BE) and the duodenum of healthy volunteers. Images were compared with endoscopy and histopathology findings when available.

RESULTS

Thirty-eight patients were enrolled. No adverse effects were reported. The TCE device swallowing rate was 34 of 38 (89%). The appearance of a physiologic upper GI wall, including its microscopic pathology, was visualized with a tissue coverage of 85.4% ± 14.9% and 90.3% ± 6.8% in the esophagus of BE patients with and without endoscopic evidence of a hiatal hernia, respectively, as well as 84.8% ± 7.4% in the duodenum. A blinded comparison of TCE and endoscopic BE measurements showed a strong to very strong correlation (r = 0.7-0.83; P < .05) for circumferential extent and a strong correlation (r = 0.77-0.78; P < .01) for maximum extent (Prague classification). TCE interobserver correlation was very strong, at r = 0.92 and r = 0.84 (P < .01), for Prague classification circumferential (C) and maximal (M) length measurements, respectively.

CONCLUSIONS

TCE is a safe and feasible procedure for obtaining high-resolution microscopic images of the upper GI tract without endoscopic assistance or sedation.

Analysis of factors associated with extended recovery time after colonoscopy

Background & aims

A common limiting factor in the throughput of gastrointestinal endoscopy units is the availability of space for patients to recover post-procedure. This study sought to identify predictors of abnormally long recovery time after colonoscopy performed with procedural sedation. In clinical research, this type of study would be performed using only one regression modeling approach. A goal of this study was to apply various “machine learning” techniques to see if better prediction could be achieved.

Methods

Procedural data for 31,442 colonoscopies performed on 29,905 adult patients at Massachusetts General Hospital from 2011 to 2015 were analyzed to identify potential predictors of long recovery times. These data included the identities of hospital personnel, and the initial statistical analysis focused on the impact of these personnel on recovery time via multivariate logistic regression. Secondary analyses included more information on patient vitals both to identify secondary predictors and to predict long recoveries using more complex techniques.

Results

In univariate analysis, the endoscopist, procedure room nurse, recovery room nurse, and surgical technician all showed a statistically significant relationship to long recovery times, with p-value below 0.0001 in all cases. In the multivariate logistic regression, the most significant predictor of a long recovery time was the identity of the recovery room nurse, with the endoscopist also showing a statistically significant relationship with a weaker effect. Complex techniques led to a negligible improvement over simple techniques in prediction of long recovery periods.

Conclusion

The hospital personnel involved in performing a colonoscopy show a strong association with the likelihood of a patient spending an abnormally long time recovering from the procedure, with the most pronounced effect for the nurse in the recovery room. The application of more advanced approaches to improve prediction in this clinical data set only yielded modest improvements.

Surgical vs Endoscopic Management of T1 Esophageal Adenocarcinoma: A Modeling Decision Analysis

BACKGROUND & AIMS

Although treatment of T1a esophageal adenocarcinoma (EAC) is shifting from esophagectomy to endoscopic therapy, T1b EACs are considered too high risk to be treated endoscopically. We investigated the effectiveness and cost effectiveness of esophagectomy vs endoscopic therapy for T1a and T1b EACs, and the effects of age and comorbidities, using a decision analytic Markov model.

METHODS

We developed a model to simulate a hypothetical cohort of men 75 years old with Charlson comorbidity index scores of 0 and either T1aN0M0 or T1bN0M0 EAC, as a base case. We used the model to compare the effects of esophagectomy vs serial endoscopic therapy. We performed sensitivity analyses based on age at diagnosis of 60-85 years, comorbidity indices of 0-2, and utilities. Post-procedure cancer-specific mortality was derived from the Surveillance, Epidemiology, and End Results Medicare database.

RESULTS

In the T1a base case, esophagectomy yielded more unadjusted life years than endoscopic therapy (6.97 vs 6.81), but fewer quality-adjusted life years (QALYs, 4.95 for esophagectomy vs 5.22 for endoscopic therapy). In the T1b base case, esophagectomy yielded more unadjusted life years than endoscopic therapy (5.73 vs 5.01) and QALYs (4.07 vs 3.85 for endoscopic therapy), but was not cost effective (incremental cost-effectiveness ratio $156,981). Sensitivity analyses showed endoscopic therapy optimized QALYs for patients more than 80 years old with a comorbidity index of 1 or 2, or if the ratio of post-esophagectomy to post-endoscopic therapy utilities was below 0.875.

CONCLUSION

In a Markov model, we showed that endoscopic therapy of T1a EAC yields more QALYs and is more cost effective than esophagectomy for patients of all ages and comorbidity indices tested. In contrast, selection of therapy for T1b EAC depends on age and comorbidities, due to surgical mortality and the competing risk of non-cancer death.

Clinical Translation of Tethered Confocal Microscopy Capsule for Unsedated Diagnosis of Eosinophilic Esophagitis

Esophagogastroduodenoscopy (EGD) is a widely used procedure, posing significant financial burden on both healthcare systems and patients. Moreover, EGD is time consuming, sometimes difficult to tolerate, and suffers from an imperfect diagnostic yield as the limited number of collected biopsies does not represent the whole organ. In this paper, we report on technological and clinical feasibility of a swallowable tethered endomicroscopy capsule, which is administered without sedation, to image large regions of esophageal and gastric mucosa at the cellular level. To demonstrate imaging capabilities, we conducted a human pilot study (n = 17) on Eosinophilic Esophagitis (EoE) patients and healthy volunteers from which representative cases are presented and discussed. Results indicate that, compared to endoscopic biopsy, unsedated tethered capsule endomicroscopy obtains orders of magnitude more cellular information while successfully resolving characteristic tissue microscopic features such as stratified squamous epithelium, lamina propria papillae, intraepithelial eosinophils, and gastric cardia and body/fundic mucosa epithelia. Based on the major import of whole organ, cellular-level microscopy to obviate sampling error and the clear cost and convenience advantages of unsedated procedure, we believe that this tool has the potential to become a simpler and more effective device for diagnosing and monitoring the therapeutic response of EoE and other esophageal diseases.

Optical coherence tomography in gastroenterology: a review and future outlook

Optical coherence tomography (OCT) is an imaging technique optically analogous to ultrasound that can generate depth-resolved images with micrometer-scale resolution. Advances in fiber optics and miniaturized actuation technologies allow OCT imaging of the human body and further expand OCT utilization in applications including but not limited to cardiology and gastroenterology. This review article provides an overview of current OCT development and its clinical utility in the gastrointestinal tract, including disease detection/differentiation and endoscopic therapy guidance, as well as a discussion of its future applications.

Safety and efficacy of endoscopic spray cryotherapy for esophageal cancer

Although surgery is traditionally the standard of care for esophageal cancer, esophagectomy carries significant morbidity. Alternative endoscopic therapies are needed for patients who are not candidates for conventional treatment. The objective of this study is to assess the safety, efficacy, and tolerability of spray cryotherapy of esophageal adenocarcinoma. This study includes patients with esophageal adenocarcinoma who had failed or were not candidates for conventional therapy enrolled retrospectively and prospectively in an open-label registry and patients in a retrospective cohort from 11 academic and community practices. Endoscopic spray cryotherapy was performed until biopsy proven local tumor eradication or until treatment was halted due to progression of disease, patient withdrawal or comorbidities. Eighty-eight patients with esophageal adenocarcinoma (median age 76, 80.7% male, mean length 5.1 cm) underwent 359 treatments (mean 4.4 per patient). Tumor stages included 39 with T1a, 25 with T1b, 9 with unspecified T1, and 15 with T2. Eighty-six patients completed treatment with complete response of intraluminal disease in 55.8%, including complete response in 76.3% for T1a, 45.8% for T1b, 66.2% for all T1, and 6.7% for T2. Mean follow-up was 18.4 months. There were no deaths or perforations related to spray cryotherapy. Strictures developed in 12 of 88 patients (13.6%) but were present before spray cryotherapy in 3 of 12. This study suggests that endoscopic spray cryotherapy is a safe, well-tolerated, and effective treatment option for early esophageal adenocarcinoma.

ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED): a study protocol for a randomized controlled trial

BACKGROUND

Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties.

METHODS/DESIGN

ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function.

DISCUSSION

Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers.

TRIAL REGISTRATION

This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769 . Registered on 16 March 2015.

Large-area spectrally encoded confocal endomicroscopy of the human esophagus in vivo

BACKGROUND AND OBJECTIVE

Diagnosis of esophageal diseases is often hampered by sampling errors that are inherent in endoscopic biopsy, the standard of care. Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal endomicroscopy technology that has the potential to visualize cellular features from large regions of the esophagus, greatly decreasing the likelihood of sampling error. In this paper, we report results from a pilot clinical study imaging the human esophagus in vivo with a prototype SECM endoscopic probe.

MATERIALS AND METHODS

In this pilot clinical study, six patients undergoing esophagogastroduodenoscopy (EGD) for surveillance of Barrett's esophagus (BE) were imaged with the SECM endoscopic probe. The device had a diameter of 7 mm, a length of 2 m, and a rapid-exchange guide wire provision for esophageal placement. During EGD, the distal portion of the esophagus of each patient was sprayed with 2.5% acetic acid to enhance nuclear contrast. The SECM endoscopic probe was then introduced over the guide wire to the distal esophagus and large-area confocal images were obtained by helically scanning the optics within the SECM probe.

RESULTS

Large area confocal images of the distal esophagus (image length = 4.3-10 cm; image width = 2.2 cm) were rapidly acquired at a rate of ∼9 mm² /second, resulting in short procedural times (1.8-4 minutes). SECM enabled the visualization of clinically relevant architectural and cellular features of the proximal stomach and normal and diseased esophagus, including squamous cell nuclei, BE glands, and goblet cells.

CONCLUSIONS

This study demonstrates that comprehensive spectrally encoded confocal endomicroscopy is feasible and can be used to visualize architectural and cellular microscopic features from large segments of the distal esophagus at the gastroesophageal junction. By providing microscopic images that are less subject to sampling error, this technology may find utility in guiding biopsy and planning and assessing endoscopic therapy. Lasers Surg. Med. 49:233-239, 2017. © 2016 Wiley Periodicals, Inc.

Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy

Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett's esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus light approximately 500 µm outside the capsule wall and the best quality images are obtained when the tissue is in full contact with the capsule, it is crucial to provide feedback for the operator about tissue contact during the imaging procedure. In this study, we developed a fully automated algorithm for the segmentation of in vivo OCT-TCE data sets and characterization of the esophageal wall. The algorithm provides a two-dimensional representation of both the contact map from the data collected in human clinical studies as well as a tissue map depicting areas of BE with or without dysplasia. Results suggest that these techniques can potentially improve the current TCE data acquisition procedure and provide an efficient characterization of the diseased esophageal wall.

Safety and efficacy of endoscopic spray cryotherapy for esophageal cancer

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Background: Although surgery is traditionally the standard of care for esophageal cancer, esophagectomy carries significant morbidity and mortality. Alternative endoscopic therapies are needed for patients who are not candidates for conventional treatment. The objective of this study was to assess the safety, efficacy, and tolerability of spray cryotherapy of esophageal cancer. Methods: This study includes patients enrolled retrospectively and prospectively in an open-label registry and patients in a retrospective cohort from twelve academic and community practices. Endoscopic spray cryotherapy was performed until local tumor eradication was confirmed by biopsy or until treatment was halted due to progression of disease, patient withdrawal or co-morbidities. Results: One-hundred and eight patients (median age 75.5, 79.6% male, 93.5% adenocarcinoma, mean length 5.2 cm) underwent 442 treatments (mean 4.2 per patient). Tumor stages included 40 with T1a, 27 with T1b, 10 with unspecified T1, 15 with T2, and 16 with no T stage reported. One-hundred and six patients completed treatment with complete response of intraluminal disease in 54.7%, including complete response in 74.4% for T1a, 50% for T1b, 65.3% for all T1, 6.7% for T2, and 50% for those with no T stage reported. Mean follow-up was 17.3 months. There were no deaths or perforations related to spray cryotherapy. Strictures developed in 11 of 108 patients (10.2%) but were present before spray cryotherapy in 3 of 11. Conclusions: This study suggests that endoscopic spray cryotherapy is safe, well tolerated and effective for early esophageal cancer in patients who are not candidates for conventional therapy.

Tethered confocal endomicroscopy capsule for diagnosis and monitoring of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an allergic condition that is characterized by eosinophils infiltrating the esophageal wall. The treatment of the disease may require multiple follow up sedated endoscopies and biopsies to confirm elimination of eosinophils. These procedures are expensive, time consuming, and may be difficult for patients to tolerate. Here we report on the development of a confocal microscopy capsule for diagnosis and monitoring of EoE. The swallowable capsule implements a high-speed fiber-based reflectance confocal microscopy technique termed Spectrally Encoded Confocal Microscopy (SECM). SECM scans the sample in one dimension without moving parts by using wavelength swept source illumination and a diffraction grating at the back plane of the objective lens. As the wavelength of the source is tuned, the SECM optics within the 7 x 30 mm capsule are rotated using a driveshaft enclosed in a 0.8 mm flexible tether. A single rotation of the optics covered a field of view of 22 mm x 223 µm. The lateral and axial resolutions of the device were measured to be 2.1 and 14 µm, respectively. Images of Acetic Acid stained swine esophagus obtained with the capsule ex vivo and in vivo clearly showed squamous epithelial nuclei, which are smaller and less reflective than eosinophils. Imaging of esophageal biopsies from EoE patients ex vivo demonstrated the capability of this technology to visualize individual eosinophils. Based on the results of this study, we believe that this capsule will be a simpler and more effective device for diagnosing EoE and monitoring the therapeutic response of this disease.

Photometric stereo endoscopy

While color video endoscopy has enabled wide-field examination of the gastrointestinal tract, it often misses or incorrectly classifies lesions. Many of these missed lesions exhibit characteristic three-dimensional surface topographies. An endoscopic system that adds topographical measurements to conventional color imagery could therefore increase lesion detection and improve classification accuracy. We introduce photometric stereo endoscopy (PSE), a technique which allows high spatial frequency components of surface topography to be acquired simultaneously with conventional two-dimensional color imagery. We implement this technique in an endoscopic form factor and demonstrate that it can acquire the topography of small features with complex geometries and heterogeneous optical properties. PSE imaging of ex vivo human gastrointestinal tissue shows that surface topography measurements enable differentiation of abnormal shapes from surrounding normal tissue. Together, these results confirm that the topographical measurements can be obtained with relatively simple hardware in an endoscopic form factor, and suggest the potential of PSE to improve lesion detection and classification in gastrointestinal imaging.

The cost effectiveness of radiofrequency ablation for Barrett's esophagus

BACKGROUND & AIMS

Radiofrequency ablation (RFA) reduces the risk of esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus (BE) with high-grade dysplasia (HGD), but its effects in patients without dysplasia are debatable. We analyzed the effectiveness and cost effectiveness of RFA for the management of BE.

METHODS

We constructed a decision analytic Markov model. We conducted separate analyses of hypothetical cohorts of patients with BE with dysplasia (HGD or low-grade [LGD]) and without dysplasia. In the analysis of the group with HGD, we compared results of initial RFA with endoscopic surveillance with surgery when cancer was detected. In analyzing the group with LGD or no dysplasia, we compared 3 strategies: endoscopic surveillance with surgery when cancer was detected (S1), endoscopic surveillance with RFA when HGD was detected (S2), and initial RFA followed by endoscopic surveillance (S3).

RESULTS

Among patients with HGD, initial RFA was more effective and less costly than endoscopic surveillance. Among patients with LGD, when S3 was compared with S2, the incremental cost-effectiveness ratio was $18,231/quality-adjusted life-year, assuming an annual rate of progression rate from LGD to EAC of 0.5%/year. For patients without dysplasia, S2 was more effective and less costly than S1. In a comparison of S3 with S2, the incremental cost-effectiveness ratios were $205,500, $124,796, and $118,338/quality-adjusted life-year using annual rates of progression of no dysplasia to EAC of 0.12%, 0.33%, or 0.5% per year, respectively.

CONCLUSIONS

By using updated data, initial RFA might not be cost effective for patients with BE without dysplasia, within the range of plausible rates of progression of BE to EAC, and be prohibitively expensive, from a policy perspective. RFA might be cost effective for confirmed and stable LGD. Initial RFA is more effective and less costly than endoscopic surveillance in HGD.

Optical frequency domain imaging system and catheters for volumetric imaging of the human esophagus

Barrett's esophagus (BE) is a metaplastic disorder that can undergo dysplastic progression, leading to esophageal adenocarcinoma. Upper endoscopy is the standard of care for screening for BE, but this technique has a relatively low diagnostic accuracy and high cost due to the requirement of conscious sedation. Optical frequency domain imaging (OFDI) is a high-speed imaging modality that generates cross-sectional images of tissues with a resolution of approximately 10μm that is sufficient for detecting microscopic tissue architecture. In combination with a balloon-centering catheter, this method enables BE diagnosis over the entire distal esophagus.

Reflectance confocal microscopy for the diagnosis of eosinophilic esophagitis: a pilot study conducted on biopsy specimens

BACKGROUND

Diagnosis of eosinophilic esophagitis (EoE) currently requires endoscopic biopsy and histopathologic analysis of the biopsy specimens to count intraepithelial eosinophils. Reflectance confocal microscopy (RCM) is an endomicroscopy technology that is capable of obtaining high-resolution, optically sectioned images of esophageal mucosa without the administration of exogenous contrast.

OBJECTIVE

In this study, we investigated the capability of a high-speed form of RCM, termed spectrally encoded confocal microscopy (SECM), to count intraepithelial esophageal eosinophils and characterize other microscopic findings of EoE.

DESIGN

A total of 43 biopsy samples from 35 pediatric patients and 8 biopsy samples from 8 adult patients undergoing EGD for EoE were imaged by SECM immediately after their removal and then processed for routine histopathology. Two SECM readers, trained on adult cases, prospectively counted intraepithelial eosinophils and detected the presence of abscess, degranulation, and basal cell hyperplasia on SECM images from the pediatric patients. A pathologist blinded to the SECM data analyzed the same from corresponding slides.

SETTING

The Gastrointestinal Unit, Massachusetts General Hospital.

RESULTS

Eosinophils by SECM demonstrated a higher reflectance than the surrounding cells and other inflammatory cells. There was good correlation between SECM and histology maximum eosinophil counts/high-power field (R = 0.76, P < .0001). Intra- and interobserver correlations for SECM counts were very good (R = 0.93 and R = 0.92, respectively; P < .0001). For the commonly used eosinophil count cutoff of 15 per high-power field, the sensitivity and specificity of SECM for EoE were 100%. The sensitivity and specificity for abscess, degranulation, and basal cell hyperplasia were 100% and 82%, 91% and 60%, and 94% and 80%, respectively. Intra- and interobserver agreements for these microscopic features of EoE were very good (κ = 0.9/0.9, 0.84/1.0, 0.91/0.81, respectively).

LIMITATION

Ex vivo study.

CONCLUSIONS

This study demonstrates that RCM can be used to accurately count intraepithelial eosinophils and identify other microscopic abnormalities associated with EoE on freshly excised biopsy samples. These findings suggest that RCM may be developed into a tool for assessing eosinophilic infiltration in the esophagus in vivo.

Co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system

Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology.

Abstract 4739: Interactions between variants of angiogenesis pathway genes and reflux symptom, BMI, and smoking in esophageal adenocarcinoma susceptibility

Esophageal adenocarcinoma (EA) is a complex malignancy that involves multiple genetic and environmental risk factors. Genetic polymorphisms in angiogenesis pathway, gastroesophageal reflux symptoms (reflux), higher body mass index (BMI), and tobacco smoking have been individually associated with EA development. However, interactions among multiple factors in EA risk have not been well characterized. We conducted a case-only study to investigate gene-environment interactions among 145 functional/tagging SNPs of angiogenesis pathway genes, reflux, smoking, and BMI in 335 patients with EA. We used a two-stage approach to detect interactions: first, we applied random forest (RF) approach to select important interacting markers based on mean decrease in accuracy and mean decrease in GINI index; then we estimated the interaction odds ratios (ORinter) of RF selected interaction markers by case-only logistic regression, adjusting for covariates and false discovery rate (FDR). We identified twelve interaction markers that were significantly associated with EA risk (all FDR_Ps&lt;0.05). Among them, six interaction markers, including reflux*rs2295778 (HIF1AN) (ORinter=2.27; 95% CI, 1.44-3.57), reflux*rs996999 (MMP1) (ORinter=1.80; 95%CI, 1.12-2.89), reflux*rs13337626 (TSC2) (ORinter=2.18; 95%CI, 1.15-4.12), BMI*rs2114039 (PDGFRA) (ORinter=2.06; 95%CI, 1.29-3.30), BMI*rs6554164 (PDGFRA) (ORinter=1.92; 95% CI, 1.20-3.08), and BMI*rs17708574 (PDGFRB) (ORinter=1.89; 95%CI, 1.12-3.18) were significantly associated with increased risk of EA. On the other hand, six interaction markers, including reflux*rs2519757 (TSC1) (ORinter=0.43; 95% CI, 0.21-0.83), smoking*rs2295778 (HIF1AN) (ORinter=0.45; 95%CI, 0.26-0.79), smoking*rs2296188 (FLT1) (ORinter=0.50; 95%CI, 0.28-0.87), BMI*rs2296188 (FLT1) (ORinter=0.41; 95%CI, 0.24-0.73), BMI*rs11941492 (KDR) (ORinter=0.52; 95%CI, 0.32-0.85), and BMI*rs17619601 (FLT1) (ORinter=0.26; 95%CI, 0.09-0.75) were significantly associated with decreased risk of EA. These findings suggest that variants in angiogenesis pathway genes, reflux, smoking, and BMI jointly contribute to EA development through gene-environment interactions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4739.

Interactions among genetic variants in apoptosis pathway genes, reflux symptoms, body mass index, and smoking indicate two distinct etiologic patterns of esophageal adenocarcinoma

PURPOSE

Apoptosis pathway, gastroesophageal reflux symptoms (reflux), higher body mass index (BMI), and tobacco smoking have been individually associated with esophageal adenocarcinoma (EA) development. However, how multiple factors jointly affect EA risk remains unclear.

PATIENTS AND METHODS

In total, 305 patients with EA and 339 age- and sex-matched controls were studied. High-order interactions among reflux, BMI, smoking, and functional polymorphisms in five apoptotic genes (FAS, FASL, IL1B, TP53BP, and BAT3) were investigated by entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional logistic regression (LR) models.

RESULTS

In LR analysis, reflux, BMI, and smoking were significantly associated with EA risk, with reflux as the strongest individual factor. No individual single nucleotide polymorphism was associated with EA susceptibility. However, there was a two-way interaction between IL1B + 3954C>T and reflux (P = .008). In both CART and MDR analyses, reflux was also the strongest individual factor for EA risk. In individuals with reflux symptoms, CART analysis indicated that strongest interaction was among variant genotypes of IL1B + 3954C>T and BAT3S625P, higher BMI, and smoking (odds ratio [OR], 5.76; 95% CI, 2.48 to 13.38), a finding independently found using MDR analysis. In contrast, for participants without reflux symptoms, the strongest interaction was found between higher BMI and smoking (OR, 3.27; 95% CI, 1.88 to 5.68), also echoed by entropy-based MDR analysis.

CONCLUSION

Although a history of reflux is an important risk for EA, multifactor interactions also play important roles in EA risk. Gene-environment interaction patterns differ between patients with and without reflux symptoms.

Endoscopic spray cryotherapy for esophageal cancer: safety and efficacy

BACKGROUND

Few options exist for patients with localized esophageal cancer ineligible for conventional therapies. Endoscopic spray cryotherapy with low-pressure liquid nitrogen has demonstrated efficacy in this setting in early studies.

OBJECTIVE

To assess the safety and efficacy of cryotherapy in esophageal carcinoma.

DESIGN

Multicenter, retrospective cohort study.

SETTING

Ten academic and community medical centers between 2006 and 2009.

PATIENTS

Subjects with esophageal carcinoma in whom conventional therapy failed and those who refused or were ineligible for conventional therapy.

INTERVENTIONS

Cryotherapy with follow-up biopsies. Treatment was complete when tumor eradication was confirmed by biopsy or when treatment was halted because of tumor progression, patient preference, or comorbid condition.

MAIN OUTCOME MEASUREMENTS

Complete eradication of luminal cancer and adverse events.

RESULTS

Seventy-nine subjects (median age 76 years, 81% male, 94% with adenocarcinoma) were treated. Tumor stage included T1-60, T2-16, and T3/4-3. Mean tumor length was 4.0 cm (range 1-15 cm). Previous treatment including endoscopic resection, photodynamic therapy, esophagectomy, chemotherapy, and radiation therapy failed in 53 subjects (67%). Forty-nine completed treatment. Complete response of intraluminal disease was seen in 31 of 49 subjects (61.2%), including 18 of 24 (75%) with mucosal cancer. Mean (standard deviation) length of follow-up after treatment was 10.6 (8.4) months overall and 11.5 (2.8) months for T1 disease. No serious adverse events were reported. Benign stricture developed in 10 (13%), with esophageal narrowing from previous endoscopic resection, radiotherapy, or photodynamic therapy noted in 9 of 10 subjects.

LIMITATIONS

Retrospective study design, short follow-up.

CONCLUSIONS

Spray cryotherapy is safe and well tolerated for esophageal cancer. Short-term results suggest that it is effective in those who could not receive conventional treatment, especially for those with mucosal cancer.

Secular trends in patients diagnosed with Barrett's esophagus

BACKGROUND

It is not known whether there have been recent changes in demographic or clinical characteristics among patients newly diagnosed with Barrett's esophagus (BE), which could be a result of changes in disease epidemiology or of screening or surveillance effects, and could have clinical implications.

AIMS

The aim of this study was to determine whether there has been a shift in age at diagnosis of BE over the past decade. Secondary aims were to determine whether there has been a shift in patient body mass index (BMI) or BE segment length.

METHODS

An endoscopic database at a tertiary medical center was used to identify all esophagogastroduodenoscopies (EGDs) performed between 1997 and 2007. The cohort was restricted to patients newly diagnosed with BE. Pathology records were reviewed to confirm biopsy findings of intestinal metaplasia (IM).

RESULTS

BE was diagnosed in 378 subjects between 1997 and 2007. Mean age at diagnosis of BE was 60.7 +/- 14.1 years, with mean BMI of 27.4 +/- 5.2 kg/m(2) and mean BE segment length of 4.7 +/- 3.7 cm. Between 1997 and 2007 there was no significant change in mean age at diagnosis, BMI, BE segment length or in proportion of men versus women newly diagnosed.

CONCLUSIONS

Despite an increase in volume of EGDs performed in an open-access endoscopy unit between 1997 and 2007, there was no appreciable shift in age at diagnosis of BE. BMI and BE segment length among newly diagnosed patients also remained stable over this time period.

Safety and efficacy of endoscopic spray cryotherapy for Barrett's esophagus with high-grade dysplasia

BACKGROUND

Endoscopic ablation to treat Barrett's esophagus (BE) with high-grade dysplasia (HGD) is associated with a decreased incidence of esophageal adenocarcinoma. Endoscopic spray cryotherapy (CRYO) demonstrates promising preliminary data.

OBJECTIVE

To assess the safety and efficacy of CRYO in BE with HGD.

DESIGN

Multicenter, retrospective cohort study.

SETTING

Nine academic and community centers; treatment period, 2007 to 2009.

PATIENTS

Subjects with HGD confirmed by 2 pathologists. Previous EMR was allowed if residual HGD remained.

INTERVENTIONS

CRYO with follow-up biopsies.

MAIN OUTCOME MEASUREMENTS

Complete eradication of HGD with persistent low-grade dysplasia, complete eradication of all dysplasia with persistent nondysplastic intestinal metaplasia, and complete eradication of all intestinal metaplasia.

RESULTS

Ninety-eight subjects (mean age 65.4 years, 83% male) with BE and HGD (mean length 5.3 cm) underwent 333 treatments (mean 3.4 treatments per subject). There were no esophageal perforations. Strictures developed in 3 subjects. Two subjects reported severe chest pain managed with oral narcotics. One subject was hospitalized for bright red blood per rectum. Sixty subjects had completed all planned CRYO treatments and were included in the efficacy analysis. Fifty-eight subjects (97%) had complete eradication of HGD, 52 (87%) had complete eradication of all dysplasia with persistent nondysplastic intestinal metaplasia, and 34 (57%) had complete eradication of all intestinal metaplasia. Subsquamous BE was found in 2 subjects (3%).

LIMITATIONS

Nonrandomized, retrospective study with no control group, short follow-up (10.5 months), lack of centralized pathology, and use of surrogate outcome for decreased cancer risk.

CONCLUSIONS

CRYO is a safe and well-tolerated therapy for BE and HGD. Short-term results suggest that CRYO is highly effective in eradicating HGD.

Image-guided biopsy in the esophagus through comprehensive optical frequency domain imaging and laser marking: a study in living swine

BACKGROUND

Random biopsy esophageal surveillance can be subject to sampling errors, resulting in diagnostic uncertainty. Optical frequency domain imaging (OFDI) is a high-speed, 3-dimensional endoscopic microscopy technique. When deployed through a balloon-centering catheter, OFDI can automatically image the entire distal esophagus (6.0 cm length) in approximately 2 minutes.

OBJECTIVE

To test a new platform for guided biopsy that allows the operator to select target regions of interest on an OFDI dataset, and then use a laser to mark the esophagus at corresponding locations. The specific goals include determining the optimal laser parameters, testing the accuracy of the laser marking process, evaluating the endoscopic visibility of the laser marks, and assessing the amount of mucosal damage produced by the laser.

DESIGN

Experimental study conducted in 5 swine in vivo.

SETTING

Massachusetts General Hospital.

MAIN OUTCOME MEASUREMENTS

Success rate, including endoscopic visibility of laser marks and accuracy of the laser marking process for selected target sites, and extent of the thermal damage caused by the laser marks.

RESULTS

All of the laser-induced marks were visible by endoscopy. Target locations were correctly marked with a success rate of 97.07% (95% confidence interval, 89.8%-99.7%). Thermal damage was limited to the superficial layers of the mucosa and was observed to partially heal within 2 days.

LIMITATIONS

An animal study with artificially placed targets to simulate pathology.

CONCLUSIONS

The study demonstrates that laser marking of esophageal sites identified in comprehensive OFDI datasets is feasible and can be performed with sufficient accuracy, precision, and visibility to guide biopsy in vivo.

Comprehensive imaging of gastroesophageal biopsy samples by spectrally encoded confocal microscopy

BACKGROUND

Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technique that has the potential to be used for acquiring comprehensive images of the entire distal esophagus endoscopically with subcellular resolution.

OBJECTIVE

The goal of this study was to demonstrate large-area SECM in upper GI tissues and to determine whether the images contain microstructural information that is useful for pathologic diagnosis.

DESIGN

A feasibility study.

SETTING

Gastrointestinal Unit, Massachusetts General Hospital.

PATIENTS

Fifty biopsy samples from 36 patients undergoing routine EGD were imaged by SECM, in their entirety, immediately after their removal.

RESULTS

The microstructure seen in the SECM images was similar to that seen by histopathology. Gastric cardia mucosa was clearly differentiated from squamous mucosa. Gastric fundic/body type mucosa showed more tightly packed glands than gastric cardia mucosa. Fundic gland polyps showed cystically dilated glands lined with cuboidal epithelium. The presence of intraepithelial eosinophils was detected with the cells demonstrating a characteristic bilobed nucleus. Specialized intestinal metaplasia was identified by columnar epithelium and the presence of goblet cells. Barrett's esophagus (BE) with dysplasia was differentiated from specialized intestinal metaplasia by the loss of nuclear polarity and disorganized glandular architecture.

LIMITATIONS

Ex vivo, descriptive study.

CONCLUSIONS

Large-area SECM images of gastroesophageal biopsy samples enabled the visualization of both subcellular and architectural features of various upper GI mucosal types and were similar to the corresponding histopathologic slides. These results suggest that the development of an endoscopic SECM probe is merited.

Treatment of Barrett's esophagus with high-grade dysplasia or cancer: predictors of surgical versus endoscopic therapy

BACKGROUND & AIMS

Patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma are at risk of progression to invasive carcinoma. Both esophagectomy and endoscopic ablation are treatment options. The aim of this study was to identify predictors of surgical versus endoscopic therapy at a tertiary center.

METHODS

An institutional database identified patients with Barrett's esophagus between 2003 and 2007. Demographic data and International Classification of Diseases-9th revision codes for esophagectomy, endoscopic ablation, as well as selected medical comorbidities were retrieved. Individual endoscopy, surgical, and pathology reports were reviewed.

RESULTS

Among 2107 individuals with Barrett's esophagus, 79 underwent esophagectomy and 80 underwent endoscopic ablation. The mean age was 63.1 +/- 10.6 years in the surgical group and 69.7 +/- 9.4 years in the ablation group (P < .0001). Among high-grade dysplasia/intramucosal carcinoma patients, 9 of 76 (12%) first seen by a gastroenterologist underwent esophagectomy, whereas 18 of 21 (86%) first seen by a surgeon underwent esophagectomy. In a logistic regression model, factors associated independently with esophagectomy were as follows: patient age of 60 or younger (odds ratio [OR], 4.95; 95% confidence interval [CI], 1.65-14.9), cancer stage T1sm or greater (OR, 16.0; 95% CI, 5.60-45.6), and initial consultation performed by a surgeon (vs gastroenterologist) (OR, 35.1; 95% CI, 9.58-129).

CONCLUSIONS

Patient age and cancer stage predict treatment modality for Barrett's esophagus with neoplasia. Treatment choice is influenced further by whether the initial evaluation is performed by a gastroenterologist or a surgeon.

Patient preferences for the chemoprevention of esophageal adenocarcinoma in Barrett's esophagus

OBJECTIVES

Although evidence suggests that aspirin and celecoxib may reduce the risk of esophageal adenocarcinoma (EAC) in patients with Barrett's esophagus (BE), these drugs can also cause harmful side effects. Our aim was to determine and characterize preferences for these two drugs in patients with BE.

METHODS

Preferences data were collected from recruited BE patients using a customized questionnaire, which incorporated standard risk communication techniques. Summary profiles outlined the benefits and harms of celecoxib and aspirin presented anonymously. Both drugs were portrayed as reducing the risk of EAC and increasing the risk of GI events. However, celecoxib increased the risk of myocardial infarction (MI) while aspirin reduced the risk. Factors influencing patient acceptance of each drug were analyzed.

RESULTS

One hundred of 109 (92%) subjects completed the study. Under base case conditions, 15% stated that they would take celecoxib and 76% aspirin (P < 0.0001). Patients identified the greater risk of MI as the primary reason for their unwillingness to take celecoxib and the lower risk of EAC for aspirin. Even in scenarios in which the benefits of celecoxib were improved and the harms reduced, a majority continued to find it unacceptable.

CONCLUSIONS

A majority of those surveyed stated that they would take aspirin but would not take celecoxib. Most patients are interested in EAC chemoprevention, but the amount of protection and the side effect profile of a drug determine its acceptability. These data can inform physicians regarding the tradeoffs patients are willing to consider for chemoprevention.

Comprehensive microscopy of the esophagus in human patients with optical frequency domain imaging

BACKGROUND

Optical coherence tomography (OCT) is a cross-sectional, high-resolution imaging modality that has been shown to accurately differentiate esophageal specialized intestinal metaplasia (SIM) from gastric cardia at the squamocolumnar junction (SCJ) and diagnose high-grade dysplasia and intramucosal carcinoma in patients with SIM. The clinical utility of OCT has been limited, however, by its inability to acquire images over large areas.

OBJECTIVE

The aim of this study was to use recently developed high-speed OCT technology, termed optical frequency domain imaging (OFDI), and a new balloon-centering catheter (2.5 cm diameter) to demonstrate the feasibility of large area, comprehensive optical microscopy of the entire distal esophagus (approximately 6.0 cm) in patients.

DESIGN

A pilot feasibility study.

SETTING

Massachusetts General Hospital.

PATIENTS

Twelve patients undergoing routine EGD.

RESULTS

Comprehensive microscopy of the distal esophagus was successfully performed in 10 patients with the OFDI system and balloon catheter. There were no complications resulting from the imaging procedure. Volumetric data sets were acquired in less than 2 minutes. OFDI images at the SCJ showed a variety of microscopic features that were consistent with histopathologic findings, including squamous mucosa, cardia, SIM with and without dysplasia, and esophageal erosion.

LIMITATIONS

Inability to obtain direct correlation of OFDI data and histopathologic diagnoses.

CONCLUSIONS

Comprehensive volumetric microscopy of the human distal esophagus was successfully demonstrated with OFDI and a balloon-centering catheter, providing a wealth of detailed information about the structure of the esophageal wall. This technique will support future studies to compare OFDI image information with histopathologic diagnoses.

Genetic polymorphisms of VEGF, interactions with cigarette smoking exposure and esophageal adenocarcinoma risk

Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis in the process of tumor growth and metastasis in esophageal adenocarcinoma (EA). Polymorphisms in the VEGF gene have been associated with altered VEGF expression and plasma VEGF levels. We hypothesized that polymorphisms of VEGF may contribute to EA risk. Functional polymorphisms in the VEGF gene (-460C/T, +405C/G and +936C/T) were determined in 308 patients with EA and 546 healthy controls. Logistic regression analysis was employed to assess the associations between genotypes, haplotypes of VEGF and EA risk, adjusting for multiple confounding factors. Compared with the +936CC genotype, the combined +936CT+TT genotypes were significantly associated with increased risk of developing EA, with adjusted odds ratio (OR) = 1.49 [95% confidence interval (CI), 1.05-2.12; P = 0.027]. The -460CT+CC were associated with increased risk of EA in smokers (adjusted OR = 1.57; 95% CI, 1.07-2.30; P = 0.021), whereas the -460CT/CC were associated with decreased risk of EA (adjusted OR = 0.47; 95% CI, 0.25-0.91; P = 0.025) in non-smokers. Compared with non-smokers with the +460TT, smokers with the +460CT+CC had significantly higher risk of EA (adjusted OR = 3.32; 95% CI, 1.56-7.10; P = 0.002). No overall or interacting association with EA risk was found for the +405C/G polymorphism. Haplotype CGT (-460C/+405G/+936T) was significantly associated with higher risk of EA (adjusted OR = 1.70; 95% CI, 1.04-2.73; P = 0.034). These results suggested that cigarette smoking modifies the association between VEGF polymorphisms and EA risk among Caucasians.

A functional epidermal growth factor (EGF) polymorphism, EGF serum levels, and esophageal adenocarcinoma risk and outcome

PURPOSE

The epidermal growth factor (EGF) pathway is important in esophageal adenocarcinoma (EAC) tumorigenesis. We hypothesized that the EGF A61G homozygous variant genotype (GG) is (a) both a risk and poor prognostic factor for EAC and (b) associated with higher EGF serum levels in individuals with gastroesophageal reflux disease (GERD).

EXPERIMENTAL DESIGN

Using unconditional logistic regression, we compared EGF A61G in 312 EAC cases and 447 GERD-free controls, adjusting for age, gender, smoking history, and healthy adult body mass index. Using the method of Kaplan and Meier, log-rank tests, and Cox proportional hazard models, we correlated EGF A61G with overall and failure-free survival in the EAC cases. Serum EGF levels and EGF genotype (G/G versus others) were correlated in 144 GERD patients using Wilcoxon rank sum tests.

RESULTS

The EGF A61G G/G genotype conferred increased EAC risk, with an adjusted odds ratio of 1.81 (95% confidence interval, 1.2-2.7), and was even higher in the subgroup of EAC patients with concurrent Barrett's esophagus (adjusted odds ratio, 2.18; 95% confidence interval, 1.3-3.7). However, EGF A61G was not associated with a more aggressive phenotype or prognosis in EAC patients. Higher serum EGF levels were found in GERD patients carrying G/G compared with A/A or A/G (P = 0.03, Wilcoxon rank sum test).

CONCLUSION

The EGF A61G G/G genotype is associated with a near 2-fold greater risk of EAC. The G/G allele was also associated with higher EGF levels in tumor-free patients with GERD. EGF genotyping can potentially identify high-risk patients with GERD and Barrett's metaplasia who might benefit from increased surveillance.

Patient predictors of esophageal stricture development after photodynamic therapy

BACKGROUND & AIMS

The most common significant adverse event after photodynamic therapy (PDT) with porfimer sodium is esophageal stricture formation. This study assessed whether pretreatment variables, including prior endoscopic therapy for Barrett's esophagus, are associated with post-PDT stricturing.

METHODS

Data from all patients who had undergone PDT with porfimer sodium for Barrett's esophagus with high-grade dysplasia, intramucosal carcinoma, or T1 cancer at our institution since 1997 were reviewed.

RESULTS

One hundred sixteen patients underwent 160 courses of PDT. The incidence of stricture formation after index PDT was 16% (19/116). For all PDT courses, the overall incidence of stricture was 23% (37/160). Stricture rate was significantly higher after a second PDT course compared with index PDT (43% vs 16%, P = .0007). There was no association between post-PDT stricture development and age, gender, body mass index, or prior endoscopic mucosal resection. Patients who developed a stricture had a longer length of Barrett's esophagus before treatment than those who did not develop a stricture (7.7 vs 5.7 cm for index PDT only, P = .025; 7.4 vs 5.7 cm for all PDT courses, P = .007). Length of Barrett's esophagus, multiple PDT courses, and presence of intramucosal carcinoma on pretreatment pathology were independent predictors of post-PDT stricture in a stepwise logistic regression analysis controlling for treatment variables, including treatment length.

CONCLUSIONS

An increased risk of stricture development was seen after multiple courses of PDT. An association between post-PDT stricture and length of Barrett's esophagus but not treatment length was also found. Endoscopic mucosal resection did not appear to influence the likelihood of stricture development after porfimer sodium-based PDT.

Polymorphisms of inflammatory and metalloproteinase genes, Helicobacter pylori infection and the risk of oesophageal adenocarcinoma

Helicobacter pylori (HP) infection appears protective against oesophageal adenocarcinoma (EA) risk. Matrix metalloproteinases (MMPs) are released in the presence of HP infection. In MMP2 wild-type individuals, HP was significantly protective of EA risk (adjusted odds ratio: 0.29; 95% confidence interval=0.1-0.7). Matrix metalloproteinases may modulate the EA-HP relationship.

Comprehensive esophageal microscopy by using optical frequency-domain imaging (with video)

BACKGROUND

Optical coherence tomography (OCT) has been used for high-resolution endoscopic imaging and diagnosis of specialized intestinal metaplasia, dysplasia, and intramucosal carcinoma of the esophagus. However, the relatively slow image-acquisition rate of the present OCT systems inhibits wide-field imaging and limits the clinical utility of OCT for diagnostic imaging in patients with Barrett's esophagus.

OBJECTIVE

This study describes a new optical imaging technology, optical frequency-domain imaging (OFDI), derived from OCT, that enables comprehensive imaging of large esophageal segments with microscopic resolution.

DESIGN

A prototype OFDI system was developed for endoscopic imaging. The system was used in combination with a balloon-centering catheter to comprehensively image the distal esophagus in swine.

RESULTS

Volumetric images of the mucosa and portions of the muscularis propria were obtained for 4.5-cm-long segments. Image resolution was 7 microm in depth and 30 microm parallel to the lumen, and provided clear delineation of each mucosal layer. The 3-dimensional data sets were used to create cross-sectional microscopic images, as well as vascular maps of the esophagus. Submucosal vessels and capillaries were visualized by using Doppler-flow processing.

CONCLUSIONS

Comprehensive microscopic imaging of the distal esophagus in vivo by using OFDI is feasible. The unique capabilities of this technology for obtaining detailed information of tissue microstructure over large mucosal areas may open up new possibilities for improving the management of patients with Barrett's esophagus.

Buried Dysplasia and Early Adenocarcinoma Arising in Barrett Esophagus After Porfimer-photodynamic Therapy

The restoration of squamous epithelium after photodynamic therapy (PDT) for Barrett esophagus (BE) and its related neoplasms has been noted. It may result in the development of buried neoplasms and/or BE underneath restored squamous epithelium which maintain their potential for malignant transformation. The purpose of this study was to evaluate the prevalence, endoscopic, and histologic characteristics and also response to further treatment of buried neoplastic epithelium developing after PDT. Fifty-two BE patients with high-grade dysplasia (n=19), intramucosal adenocarcinoma (n=28), and invasive adenocarcinoma (n=5) were treated with porfimer PDT. Buried neoplasms completely covered by squamous epithelium were seen in 1 patient before and in 13 patients after PDT. Their prevalence was 0.6% and 7.4% of pre and post-PDT biopsy levels positive for neoplasia (P=0.001). Buried neoplasms, representing the highest grade of residual neoplasm, were noted in a series of 11 post-PDT endoscopies (7.1% of 155 post-PDT endoscopies with neoplastic diagnoses) of 8 patients. Their occurrence after PDT was neither associated with the length of BE, the diffuseness of neoplasms nor the presence of buried lesions before treatment. There was no prevalent location for these lesions in relation to the original segment of BE, although the majority of both surface and buried neoplasms were found in the prior neoplastic sites. Patients with buried neoplasms responded to further treatment similarly to those with only surface neoplasms (8 of 13 vs. 17 of 24) (P=0.33). In conclusion, buried neoplasms are not uncommon after PDT. Thorough endoscopic surveillance with extensive biopsies, especially of the sites previously positive for neoplasia is important to avoid overlooking buried neoplasms that may progress.

XRCC1 and XPD polymorphisms and esophageal adenocarcinoma risk

DNA damage is important in the pathogenesis of esophageal adenocarcinoma (EA). Polymorphic variants in DNA repair genes may be modifiers of the risk of EA through their role in altering human host response to gastroesophageal acid reflux, a well-described risk factor for EA. We studied the role of genetic polymorphisms of two key DNA repair genes, xeroderma pigmentosum group D (XPD) (Asp312Asn and Lys751Gln) in the nucleotide excision repair (NER) pathway and X-ray repair cross-complementing gene 1 (XRCC1) (Arg399Gln) in the base excision repair (BER) pathway, in the development of EA in 183 cases and 336 frequency-matched controls for age, gender and race. Genomic DNA was extracted from blood samples. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from logistic regression models, adjusted for body mass index at 18 years of age, smoking and alcohol exposure. The variant genotypes of XPD Lys751Gln polymorphism were associated with a higher risk of EA; the adjusted OR comparing Gln/Gln + Lys/Gln with Lys/Lys was 1.49 (95% CI: 1.02-2.14). Although no significant relationships were found for the XRCC1 Arg399Gln polymorphism alone, this polymorphism did modify the relationship between XPD Lys751Gln and EA risk; when both polymorphisms were evaluated together, adding the number of variant alleles of the two polymorphisms resulted in a significant trend (trend test, P = 0.008); compared with individuals with no variant alleles (n = 88), the adjusted ORs of developing EA are 1.49 (95% CI: 0.88-2.59), 1.69 (95% CI: 0.98-2.96) and 2.58 (95% CI: 1.31-5.06) for one (n = 195), two (n = 166) and three or four variant alleles (n = 70), respectively. No relationships were found for the XPD Asp312Asn polymorphism. We conclude that combined NER and BER pathways are important to the development of EA.

Identifying intestinal metaplasia at the squamocolumnar junction by using optical coherence tomography

BACKGROUND

Optical coherence tomography (OCT) is an optical imaging method that produces high-resolution cross-sectional images of the esophagus. The accuracy of OCT for differentiating tissue types at the squamocolumnar junction (SCJ) has not been established.

OBJECTIVE

The purpose of this study was to identify and validate OCT image criteria for distinguishing metaplastic from nonmetaplastic tissue at the SCJ.

DESIGN

A total of 196 biopsy-correlated OCT images of the SCJ were acquired from 113 patients undergoing upper endoscopy. A pathologist blinded to the OCT results reviewed each pathology specimen and determined the presence of the following histopathology: gastric cardia, squamous mucosa, pancreatic metaplasia, and intestinal metaplasia. An algorithm for diagnosing specialized intestinal metaplasia (SIM) was created by reviewing a training set of 40 biopsy-correlated OCT images. Two blinded investigators prospectively tested the algorithm on a validation set of 123 images.

RESULTS

OCT images of squamous mucosa were characterized by a layered appearance without epithelial glands; gastric cardia, by vertical pit and gland structure, a well-defined epithelial surface reflectivity, and relatively poor image penetration; and SIM by an irregular architecture and good image penetration. The OCT criteria were 85% sensitive and 95% specific for SIM when applied retrospectively to the training set. When applied to the validation set, the algorithm was 81% sensitive for both OCT readers and 66% and 57% specific for diagnosing SIM. The interobserver agreement was good (kappa = 0.53).

CONCLUSIONS

OCT imaging can identify SIM at the SCJ with an accuracy similar to that of endoscopy.

Comprehensive volumetric optical microscopy in vivo

Comprehensive volumetric microscopy of epithelial, mucosal and endothelial tissues in living human patients would have a profound impact in medicine by enabling diagnostic imaging at the cellular level over large surface areas. Considering the vast area of these tissues with respect to the desired sampling interval, achieving this goal requires rapid sampling. Although noninvasive diagnostic technologies are preferred, many applications could be served by minimally invasive instruments capable of accessing remote locations within the body. We have developed a fiber-optic imaging technique termed optical frequency-domain imaging (OFDI) that satisfies these requirements by rapidly acquiring high-resolution, cross-sectional images through flexible, narrow-diameter catheters. Using a prototype system, we show comprehensive microscopy of esophageal mucosa and of coronary arteries in vivo. Our pilot study results suggest that this technology may be a useful clinical tool for comprehensive diagnostic imaging for epithelial disease and for evaluating coronary pathology and iatrogenic effects.

Multilayered epithelium may be found in patients with Barrett's epithelium and dysplasia or adenocarcinoma

To determine if multilayered epithelium (MLE) is a useful prognostic indicator for a benign natural history of Barrett's epithelium, we evaluated endoscopic biopsies from patients with Barrett's epithelium without and with dysplasia and/or adenocarcinoma and from non-Barrett's controls for the presence of MLE. MLE was found in 6% of non-Barrett's controls, 30% of Barrett's patients with no dysplasia, and 14% of Barrett's patients with dysplasia and/or adenocarcinoma. MLE was significantly associated with shorter lengths of Barrett's epithelium in both Barrett's groups. Three of 5 photodynamic therapy patients were noted to develop MLE after therapy. MLE may be found in patients with dysplasia and/or adenocarcinoma and after photodynamic therapy; its presence is not useful as a prognostic indicator for a more benign course of Barrett's. This study confirms that MLE is significantly associated with shorter lengths of Barrett's epithelium.

Quality of life in patients with various Barrett's esophagus associated health states

Background

The management of Barrett's esophagus (BE), particularly high grade dysplasia (HGD), is an area of much debate and controversy. Surgical esophagectomy, intensive endoscopic surveillance and mucosal ablative techniques, especially photodynamic therapy (PDT), have been proposed as possible management strategies. The purpose of this study was to determine the health related quality of life associated with Barrett's esophagus and many of the pivotal health states associated with Barrett's HGD management.

Methods

20 patients with Barrett's esophagus were enrolled in a pilot survey study at a large urban hospital. The utility of Barrett's esophagus without dysplasia (current health state) as well as various health states associated with HGD management (hypothetical states as the subject did not have HGD) were measured using a validated health utility instrument (Paper Standard Gamble). These specific health states were chosen for the study because they are considered pivotal in Barrett's HGD decision making. Information regarding Barrett's HGD was presented to the subject in a standardized format that was designed to be easily comprehendible.

Results

The average utility scores (0–1 with 0 = death and 1 = perfect health) for the various Barrett's esophagus associated states were: BE without dysplasia-0.95; Post-esophagectomy for HGD with dysphagia-0.92; Post-PDT for HGD with recurrence uncertainty-0.93; Post-PDT for HGD with recurrence uncertainty and dysphagia-0.91; Intensive endoscopic surveillance for HGD-0.90.

Conclusion

We present the scores for utilities associated with Barrett's esophagus as well as various states associated with the management of HGD. The results of our study may be useful in advising patients and providers regarding expected outcomes of the various HGD management strategies as well as providing utility scores for future cost-effectiveness analyses.

Endoscopic mucosal resection: an improved diagnostic procedure for early gastroesophageal epithelial neoplasms

Endoscopic mucosal resection (EMR), which is advocated for the treatment of early (superficial) gastroesophageal neoplasms, has also been alluded to represent a superior diagnostic and staging modality. We compared the diagnostic concordance of preceding biopsies with EMR specimens in 31 gastric and 10 esophageal EMRs consisting of 6 low-grade and 12 high-grade dysplasias, 21 intramucosal adenocarcinomas, and 2 submucosal invasive adenocarcinomas. Discrepancies were considered as either major or minor if the histologic grades differed by 2 or more, or by only 1, respectively. Discrepant and concordant cases were compared with regard to the size of lesion (maximum dimension and surface area), number of biopsy fragments, and extent of biopsy sampling (ratio between lesion size and number of biopsy fragments). These same variables were used to evaluate the differences seen between gastric and esophageal cases. Of the 41 cases, 16 (39%) had discrepant diagnoses, including 14 gastric and 2 esophageal neoplasms. A major discrepancy was seen in 2% of the cases (n = 1, gastric) and a minor discrepancy, in 15 cases. All but 2 of the discrepant cases were found to have a higher grade on EMR. The average number of biopsy fragments was 4.4 in both concordant and discrepant groups. The maximal dimension, surface area, and biopsy sampling ratios of the lesion were significantly greater in the discrepant cases than in the concordant cases. The esophageal cases trended toward having smaller size and a significantly extensive biopsy sampling. We conclude that EMR is superior to biopsy for diagnosing superficial gastroesophageal tumors. Discrepancies between the specimens occur in larger lesions (>10 mm) with less extensive biopsy sampling. EMR can substantially modify the diagnostic grade of a lesion and therefore facilitate optimal therapeutic decisions by avoiding undertreatment and overtreatment based on inaccurate grading and staging.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Helicobacter pylori in patients can be killed by visible light

BACKGROUND

Helicobacter pylori colonizes the mucus layer of the human stomach and may cause peptic ulcer and adenocarcinoma. Novel antimicrobial approaches are sought due to the occurrence of antibiotic resistance and consequent treatment failure. We report here that H. pylori is susceptible to inactivation by blue light.

STUDY DESIGN/MATERIALS AND METHODS

A controlled, prospective, blinded, trial of endoscopically delivered blue light to eradicate H. pylori in regions of the gastric antrum, in 10 patients between the ages of 21 and 80 who tested positive for H. pylori. Light (405 nm) (40 J/cm2) was delivered to a 1-cm diameter spot in the gastric antrum via optical fiber passed through the endoscope and weighed biopsies were taken from treated and control spots and colonies quantitatively cultured.

RESULTS

Blue light killed 5 logs of bacteria in vitro. The mean reduction in H. pylori colonies per gram tissue between treated and control spots was 91% (7.4+/-4.8 x 10(6) vs. 8.1+/-1.9 x 10(7), two-tailed P < 0.0001). Some patients had reductions approaching 99%. No differences were observed on histological examination of light-treated and control gastric tissue.

CONCLUSION

Blue light phototherapy may represent a novel approach to eradication of H. pylori, particularly, in patients who have failed standard antibiotic treatment.

Endoscopic confocal microscopy

PURPOSE OF REVIEW

Endoscopic confocal microscopy is a new endoscopic imaging technology that produces high-magnification cross-sectional images of the gastrointestinal epithelium during endoscopy. These high-magnification images might allow the endoscopist to make a tissue diagnosis during endoscopy without biopsy and histopathology. The purpose of this article is to review the salient features of endoscopic confocal microscopy, describe current clinical research areas using the technology, and depict its potential role in the management of gastrointestinal diseases. This review includes an overview of the technology, a review of recent publications describing its function, and a discussion of potential applications.

RECENT FINDINGS

Endoscopic confocal microscopy has been technologically feasible only for a short time; therefore, the published experience is limited. Studies describing the use of endoscopic confocal microscopy for the detection of dysplastic tissue have been limited to a single paper in which endoscopic confocal microscopy was reported to be highly sensitive and specific for the detection of colonic dysplasia in a general screening population. Active areas of investigation include detecting dysplasia in ulcerative colitis and Barrett's esophagus. A recent case report detailed the ability of endoscopic confocal microscopy to detect gastric Helicobacter pylori in vivo.

SUMMARY

Endoscopic confocal microscopy is a new imaging technology that produces high-magnification cross-sectional images of the gastrointestinal tract. Its role in detecting and managing diseases of the gastrointestinal tract has been studied in colon cancer screening and is currently being evaluated in a variety of premalignant conditions.